Showing papers on "Bioprocess published in 1993"

Biochemical production capabilities of escherichia coli

Abstract: Microbial metabolism provides at mechanism for the conversion of substrates into useful biochemicals. Utilization of microbes in industrial processes requires a modification of their natural metabolism in order to increase the efficiency of the desired conversion. Redirection of metabolic fluxes forms the basis of the newly defined field of metabolic engineering. In this study we use a flux balance based approach to study the biosynthesis of the 20 amino acids and 4 nucleotides as biochemical products. These amino acids and nucleotides are primary products of biosynthesis as well as important industrial products and precursors for the production of other biochemicals. The biosynthetic reactions of the bacterium Escherichia coli have been formulated into a metabolic network, and growth has been defined as a balanced drain on the metabolite pools corresponding to the cellular composition. Theoretical limits on the conversion of glucose, glycerol, and acetate substrates to biomass as well as the biochemical products have been computed. The substrate that results in the maximal carbon conversion to a particular product is identified. Criteria have been developed to identify metabolic constraints in the optimal solutions. The constraints of stoichiometry, energy, and redox have been determined in the conversions of glucose, glycerol, and acetate substrates into the biochemicals. Flux distributions corresponding to the maximal production of the biochemicals are presented. The goals of metabolic engineering are the optimal redirection of fluxes from generating biomass toward producing the desired biochemical. Optimal biomass generation is shown to decrease in a piecewise linear manner with increasing product formation. In some cases, synergy is observed between biochemical production and growth, leading to an increased overall carbon conversion. Balanced growth and product formation are important in a bioprocess, particularly for nonsecreted products.

Artificial intelligence and the supervision of bioprocesses (real-time knowledge-based systems and neural networks)

Abstract: The ability to supervise and control a highly non-linear and time variant bioprocess is of considerable importance to the biotechnological industries which are continually striving to obtain higher yields and improved uniformity of production. Two AI methodologies aimed at contributing to the overall intelligent monitoring and control of bioprocess operations are discussed.

Thermodynamics of enzyme-catalyzed reactions

Abstract: Chemical thermodynamics is the science that deals with transformations of matter and energy. As such, it has found wide scientific and industrial applications in treating chemical reactions and processes. The important practical side of this discipline is that it serves as a primary tool for process design, optimization, and decision-making. Examples of chemical production where thermodynamics play a major role are the production of synthetic diamonds from graphite and the production of aviation fuel from hydrocarbons. In the much younger bioprocessing industry, examples of thermodynamic applications are seen in the production of food and pharmaceutical products such as high-fructose corn syrup and semi-synthetic penicillins. Indeed, many, if not most, bioprocess applications involve enzyme catalysis.

3rd International Conference on Bioreactor and Bioprocess Fluid Dynamics

Abstract: Bioremediation bioseparation bioreactor design (fermentation or biotransformation) interaction bewteen upstream and downstream processing process aspects of new bioscience process economics and design bioleaching sterilization and medi a preparation CFD and modelling biological aspects of water treatment fouling of equipment mixing and rheological problems inthe food industry

Biological Separation of Phosphate from Ore

Abstract: The importance of microbial action in mobilization of insoluble phosphate in soils is widely recognized though the process is not well understood. Based on literature reports and on an energy conservation potential, research on the potential of using biosolubilization for the industrial processing of rock phosphate ores appears to be worth while. This paper reports on efforts to develop such a process. Activities related to the isolation and selection of phosphate solubilizing microbial species as well as those efforts to develop a bench top bioprocess unit for the continuous solubilization of phosphate ore are discussed.

SIMBIOS: a new simulation program for biotechnology with novel design

Abstract: Process simulation is a viable tool for chemical engineering process design. A large number of process simulation programs have been developed to this end, like ASPEN, PROCESS, HYSIM, just to mention a few widely known brand names. However, most of these programs have been developed to meet the needs of chemical process engineers, one notable exception being Bioprocess Simulator of ASPEN. SIMBIOS is a new program package currently under development by a Hungarian and Austrian team which is specially designed to meet requirements of bioprocess simulation. Besides offering models for most unit operations in use in bioprocess engineering, a specially developed structure ensures optimal applicability for bioprocess simulation. SIMBIOS will run on IBM compatible PC's.

Development of a regenerable glucose biosensor probe for bioprocess monitoring

Abstract: The implementation and commercialization of enzyme-based biosensors for on-line bioprocess monitoring and control has been slowed by problems relating to the in situ sterilizability of the probe and the stability of the enzyme component. A novel technology is presented here which addresses both of these difficulties. The approach is based on the reversible immobilization of enzymes conjugated with the cellulose binding domain (CBD) of cellulases from Cellulomonas fimi. A regenerable biosensor probe is configured with a cellulose matrix onto which the solubilized enzyme-CBD conjugate can be repeatedly loaded (via the attachment of the CBD) and subsequently eluted by perfusing the cellulose matrix with the appropriate loading or eluting solution. The chemical conjugation of the enzyme glucose oxidase (GOx) with CBD by glutaraldehyde is described. The GOx-CBD conjugate retained the enzymatic activity of the glucose oxidase and the binding affinity of the CBD. The GOx-CBD conjugate was used in an experimental glucose biosensor based on a platinum rotating disk electrode fitted with a cellulose immobilization matrix to demonstrate the feasibility of multiple cycles of loading and elution of the conjugate and to develop suitable protocols and reagents for the loading and elution procedures. A prototype glucose biosensor and reagent flow system were designed and built for use in fermentation monitoring. A custom-designed membrane system consisting of a sterilizable, glucose-permeable outer Nafion membrane for the sensor and a cellulose acetate coating on the indicating electrode was developed for use in a microbial fermentation. The prototype glucose biosensor was used successfully to monitor medium glucose concentration for 16.5 continuous hours during a 20 L fed-batch cultivation of E. coli in minimal medium. Michaelis-Menten enzyme kinetics were used as an empirical model for the calibration of the experimental biosensor. The development of a computer-controlled prototype glucose biosensor and fermentation monitoring system is discussed.

Bioprocess simulation in practice: joint strategy with modelling and experiments according to the formal macroapproach

Abstract: A strategy in process engineering work is explained, where bioprocesses are understood as a network between physiology and physics and where adequate simplifications are elaborated as a consequence of joint efforts between model set-up, model simulation and process model verification in experiments. Complex, nonlinear systems cannot be predicted by analyzing pieces of them separatively and, thus, need to be taken as a whole. Thereby the «formal macroapproach» is followed. The result is a process model with a high probability to be adequate even the accuracy can be quite low. As real bioprocesses are highly complex, bioprocess models will always represent approximations in a certain respect. Models serve as spiritual guide lines for better understanding of the bioprocess.

The use of a synthetic film (Bioprocess) in abrasions and second degree burns. Preliminary study in the emergency room

Abstract: This study analyzes the usage of Bioprocess in abrasions and second degree burns, observing advantages and disadvantages of this treatment. This clinical research shows an important control against pain, a good hemostatic effect, an apparent reduction of healing time, an excellent cicatrization quality.

An advanced wastewater treatment system consisting of an anaerobic fluidized bed bioreactor and an aerobic bioprocess

Abstract: An anaerobic fluidized bed (AFB) bioreactor followed by an aerobic bioprocess enables effectively simultaneous removal of suspended solids, organic matter, phosphorus and nitrogen compounds. In the AFB bioreactor, suspended solids, colloidal matter and phosphorus were coagulated with the combined use of small amount of polymerized aluminium chloride and weakly anionic polymers to generate large sized coagulated sludge which could rapidly separate from the liquid. Especially, in the summer season with high water temperature, the pelletized sludge with high effective density can be produced. The microscopic observation showed the pelletization of sewage pollutants was caused by chemical coagulation as well as bacterial growth. Above 18•K of temperature, recycling of nitrified effluent from the aerobic bioprocess to the AFBbioreactor achieved complete denitrificationandnitrificationwitha total retention time of 4h(2h in AFB bioreactor and 2h in the aerobic bioprocess) and a recirculation rate 3 times the feed rate, resulting in above 80% of total nitrogen removal efficiency. Keywords; anaerobic fluidized bed bioreactor, pelletization of sewage, nitrification, denitrification, phosphorus removal 1.は じめに 下水中には固形性(懸 濁性)と 溶解性の有機汚濁物質が含まれている。現在の下水処理システムでの最初 沈殿池における固液分離は不十分であり、微細な懸濁性成分やコロイ ド成分は後段の生物処理プロセスへの 汚濁負荷となっている。したがって前処理によって、これらの懸濁性成分の除去効率を増加させることがで きれば、活性汚泥法などの生物処理プロセスにおいて曝気時間の短縮や曝気動力の節減が可能となる、この ような観点に基づいて、最近凝集剤を添加 した り1)、 材を用いて2)、下水中の懸濁性およびコロイ ド成分 の除去率を増加させることができるプロセスが報告されている。 一方今日下 、有機汚濁成分だけでなく窒素 ・リンなどの栄養塩類の除去が可能な高度 処理プロセスの確立が望まれている。現在A2O法 、UCT法、Phoredox法 などが開発されているがいずれの処理 プロセスにおいても、脱窒 ・脱 リン反応に必要な有機炭素源が不足するために、下 ・廃水中の窒素 ・リンを バランスよく除去することの困難さや処理の安定性が低いなどの問題点が指摘されている。そこで最近、下 ・廃水中に含まれる懸濁物質中の易加水分解成分を脱窒 ・脱 リンの炭素源およびエネルギー源として利用し ようとする研究が行われている。Schonberger3)は 既存の最初沈殿池を流入下水と返送汚泥とを接触させるた めの嫌気性汚泥接触槽に変更 して、懸濁性BODを 利用したリン除去が可能な冠ASC(Extended Anaerobic Shdge Conact)プ ロセスを開発 している、またRabinowitzら4)は 下水処理プラントに新たに醗酵槽を付設 し、 初沈汚泥の酸醗酵を行い、生成する低級脂肪酸を生物学的脱 リンプロセスへ供給 し、リン除去効率の大幅な *北 海道大学工学部衛生工学科 (Dept. of Sanitary and Environmental Engineering, Hokkaido University) **月 島機械KK (Tsukishima Kikai Co., Ltd.)

Review of nonconventional bioreactor technology

Abstract: Biotechnology will significantly affect many industrial sectors in the future. Industrial sectors that will be affected include pharmaceutical, chemical, fuel, agricultural, and environmental remediation. Future research is needed to improve bioprocessing efficiency and cost-effectiveness in order to compete with traditional technologies. This report describes recent advances in bioprocess technologies and bioreactor designs and relates them to problems encountered in many industrial bioprocessing operations. The primary focus is directed towards increasing gas and vapor transfer for enhanced bioprocess kinetics as well as unproved by-product separation and removal. The advantages and disadvantages of various conceptual designs such as hollow-fiber, gas-phase, hyperbaric/hypobaric, and electrochemical bioreactors are also discussed. Specific applications that are intended for improved bioprocesses include coal desulfurization, coal liquefaction, soil bioremediation, biomass conversion to marketable chemicals, biomining, and biohydrometallurgy as well as bioprocessing of gases and vapors.

Multi-rate estimation and monitoring of process variables in a bioreactor

Abstract: This paper addresses the problem of simultaneous state and parameter estimation for a bioprocess. It proposes a formal approach to incorporate multiple rates of sampling, that typically exist in a bioprocess, so that estimation is done using all of and the most up to-date measurements. The software sensor that results from the above approach is validated using experimental data from fed-batch fermentation of Streptomyces Clavuligerus. >

Biotechnology in a new Europe

Abstract: Biotechnology, broadly defined, includes any technique that uses living organisms (or parts of organisms) to make or modify products, to improve plants or animals, or to develop micro-organisms for specific purposes. Although traditional uses of biotechnology are centuries old (e.g. baking and brewing), it is the so-called new biotechnology involving the uses of modern scientific techniques, such as RDNA technology, hybridoma technology, and bioprocess technology, that leads to issues affecting international commercialization of research and products and is the focus of this report.

Sensors for Bioprocess Monitoring and Control

Abstract: The need for robust sensors for bioprocess monitoring leading to effective control strategies is well recognized by biochemical engineers. Firstly, the ability to monitor on-line cell mass concentrations has been the goal of many re¬searchers. Secondly, the added complexity of many fermentation media contain¬ing suspended solids renders the cell concentration measurement in situ in a fermenter even more challenging. Lastly, the ability to differentiate the total cell mass from the viable fraction in situ could lead to some very exciting on-line control and optimization strategies.